17c478bd9Sstevel@tonic-gate/* 27c478bd9Sstevel@tonic-gate * CDDL HEADER START 37c478bd9Sstevel@tonic-gate * 47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 58cd45542Sraf * Common Development and Distribution License (the "License"). 68cd45542Sraf * You may not use this file except in compliance with the License. 77c478bd9Sstevel@tonic-gate * 87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 117c478bd9Sstevel@tonic-gate * and limitations under the License. 127c478bd9Sstevel@tonic-gate * 137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 187c478bd9Sstevel@tonic-gate * 197c478bd9Sstevel@tonic-gate * CDDL HEADER END 207c478bd9Sstevel@tonic-gate */ 218cd45542Sraf 227c478bd9Sstevel@tonic-gate/* 238cd45542Sraf * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 247c478bd9Sstevel@tonic-gate * Use is subject to license terms. 257c478bd9Sstevel@tonic-gate */ 267c478bd9Sstevel@tonic-gate 27*9a70fc3bSMark J. Nelson .file "getcontext.s" 287c478bd9Sstevel@tonic-gate 297c478bd9Sstevel@tonic-gate#include <sys/asm_linkage.h> 307c478bd9Sstevel@tonic-gate 317c478bd9Sstevel@tonic-gate ANSI_PRAGMA_WEAK(getcontext,function) 327c478bd9Sstevel@tonic-gate ANSI_PRAGMA_WEAK(swapcontext,function) 337c478bd9Sstevel@tonic-gate 347c478bd9Sstevel@tonic-gate#include "SYS.h" 357c478bd9Sstevel@tonic-gate#include <assym.h> 367c478bd9Sstevel@tonic-gate 377c478bd9Sstevel@tonic-gate/* 387c478bd9Sstevel@tonic-gate * getcontext() and swapcontext() are written in assembler since it has to 397c478bd9Sstevel@tonic-gate * capture the correct machine state of the caller, including 407c478bd9Sstevel@tonic-gate * the registers: %edi, %esi and %ebx. 417c478bd9Sstevel@tonic-gate * 427c478bd9Sstevel@tonic-gate * As swapcontext() is actually equivalent to getcontext() + setcontext(), 437c478bd9Sstevel@tonic-gate * swapcontext() shares the most code with getcontext(). 447c478bd9Sstevel@tonic-gate */ 457c478bd9Sstevel@tonic-gate 467c478bd9Sstevel@tonic-gate 477c478bd9Sstevel@tonic-gate#define GETCONTEXT_IMPL \ 487c478bd9Sstevel@tonic-gate movl 4(%esp), %eax; /* %eax <-- first arg: ucp */ \ 497c478bd9Sstevel@tonic-gate pushl %eax; /* push ucp for system call */ \ 508cd45542Sraf call __getcontext; /* call getcontext: syscall */ \ 517c478bd9Sstevel@tonic-gate addl $4, %esp; /* pop arg */ \ 527c478bd9Sstevel@tonic-gate andl %eax, %eax; /* if (err_ret_from_syscall) */ \ 537c478bd9Sstevel@tonic-gate je 1f; \ 547c478bd9Sstevel@tonic-gate ret; /* then return */ \ 557c478bd9Sstevel@tonic-gate1: \ 567c478bd9Sstevel@tonic-gate movl 4(%esp), %eax; /* recompute first arg */ \ 577c478bd9Sstevel@tonic-gate /* \ 587c478bd9Sstevel@tonic-gate * fix up %esp and %eip \ 597c478bd9Sstevel@tonic-gate */ \ 607c478bd9Sstevel@tonic-gate leal UC_MCONTEXT_GREGS (%eax), %edx; \ 617c478bd9Sstevel@tonic-gate /* %edx <-- &ucp->uc_mcontext.gregs */ \ 627c478bd9Sstevel@tonic-gate movl 0(%esp), %eax; /* read return PC from stack */ \ 637c478bd9Sstevel@tonic-gate movl %eax, EIP_OFF (%edx); \ 647c478bd9Sstevel@tonic-gate /* store ret PC in EIP of env var */ \ 657c478bd9Sstevel@tonic-gate leal 4(%esp), %eax; /* get caller's sp at time of call */ \ 667c478bd9Sstevel@tonic-gate movl %eax, UESP_OFF (%edx); \ 677c478bd9Sstevel@tonic-gate /* store the sp into UESP of env var */ \ 687c478bd9Sstevel@tonic-gate xorl %eax, %eax; /* return 0 */ \ 697c478bd9Sstevel@tonic-gate movl %eax, EAX_OFF (%edx); \ 707c478bd9Sstevel@tonic-gate /* getcontext returns 0 after a setcontext */ 717c478bd9Sstevel@tonic-gate 727c478bd9Sstevel@tonic-gate/* 737c478bd9Sstevel@tonic-gate * getcontext(ucontext_t *ucp) 747c478bd9Sstevel@tonic-gate */ 757c478bd9Sstevel@tonic-gate ENTRY(getcontext) 767c478bd9Sstevel@tonic-gate GETCONTEXT_IMPL 777c478bd9Sstevel@tonic-gate ret 787c478bd9Sstevel@tonic-gate SET_SIZE(getcontext) 797c478bd9Sstevel@tonic-gate 807c478bd9Sstevel@tonic-gate 817c478bd9Sstevel@tonic-gate/* 827c478bd9Sstevel@tonic-gate * swapcontext(ucontext_t *oucp, const ucontext_t *ucp) 837c478bd9Sstevel@tonic-gate */ 847c478bd9Sstevel@tonic-gate ENTRY(swapcontext) 857c478bd9Sstevel@tonic-gate GETCONTEXT_IMPL 867c478bd9Sstevel@tonic-gate / call setcontext 877c478bd9Sstevel@tonic-gate movl 8(%esp), %eax /* %eax <-- second arg: ucp */ 887c478bd9Sstevel@tonic-gate pushl %eax /* push ucp for setcontext */ 898cd45542Sraf call setcontext 907c478bd9Sstevel@tonic-gate addl $4, %esp /* pop arg: just in case */ 917c478bd9Sstevel@tonic-gate ret 927c478bd9Sstevel@tonic-gate SET_SIZE(swapcontext) 93